This invetion relates to time division multiplex (TDM) systems and is especially suited for such systems capable of voice transmission via burst analog signalling.
In a conventional TDM system a single communication path is used to concurrently carry a plurality of information. A predetermined time interval or frame is defined in which time slots are allocated and correspondence to different information channels.
For information such as digital data the time delay associated with the frame length between transmissions is normally not a problem. However, other signal such as voice require continuous signal handling capabilities.
In one approach to utilize a TDM path to carry voice, an input voice signal is converted to digital data and compressed in time so that voice duting a frame occupies only one time slot. It is demultiplexed at the receiving station by expanding in time the compressed signal.
The quality of a voice transmitted by this method suffers degradation due to transients or "glitches" associated with discontinuities between the magnitude of the signal at the end of one time slot and the beginning magnitude of the signal at the beginning of the time slot in the next frame.
It is an object of the present invention to provide an improved TDM transmitter and receiver which minimize such transients.